1. Field of the Invention
The present invention is related to a test device and particularly to a test device for a heat dissipating fan for testing if the fan wheel is joined to the housing of the fan firmly.
2. Brief Description of the Related Art
Referring to FIG. 1, the conventional heat dissipating fan 1 includes a housing 11 with a support pipe 111, a fan wheel 12, a retaining ring 13, which is disposed in the support pipe 111. The fan wheel 12 has a hub 121 and a shaft 122 mounted to the hub 121, the shaft 122 has an engaging groove 123 at an end thereof. Process for assembling the fan 1 is performed based on the following steps. First, the retaining ring 13 is placed in the support pipe 111. Then, the shaft 122 is inserted into the support pipe 111 through the retaining ring 13. Next, the fan wheel 12 is applied a force to urge the retaining ring 13 for the retaining ring 13 being able to engage with the engaging groove 123 finally.
Too large the preceding force being applied is easy to result in damaging other components beside the retaining ring 13 and too little the preceding force being applied is easy to result in the shaft 122 being incapable of engaging with the retaining ring 13 firmly. Further, some other types heat dissipating fans 1 have another end of the support pipe 111 being a blind end and it makes test with sight impossible. Hence, in order to make sure the fan wheel 12 being secured to the housing 11 firmly, several inspectors have to be assigned to pull the fan wheel 12 beside the assembling line. When the fan wheels 12 move with the pull force exerted by the inspectors, it hints that the engaging groove 123 does not engage with the retaining ring 13 completely.
As the foregoing, for securing quality of assembled heat dissipating fans 1, inspectors have to be hired to check every fan 1 and it not only incurs more production cost but also is unable to promote production efficiency. In addition, manual check often occurs careless mistakes because the pull forces applied by the inspectors are hard to keep in a constant direction.